1. Field of the Invention (Technical Field)
The invention relates to safety and security discriminators and more particularly to an apparatus and method for mechanically discriminating a unique signal utilizing a pin-in-maze structure.
2. Background Art
Discriminator devices are being proposed as safety devices in diverse areas such as automotive, aircraft, nuclear reactors, chemical processing plants and robotic handling of hazardous/radioactive material. Discriminator devices also have security applications and can be used to deny access to those not having the unique signal.
The pin-in-maze discriminator of the present invention was developed as a safety component to prevent the occurrence of catastrophic accidents. Accidents involving nuclear power plants, chemical processing plants, and airplane crashes are examples of catastrophes. These accidents are due to the failure of human made machines and are not natural disasters in themselves. Abnormal occurrences can lead to catastrophic accidents which result in great loss of life and resources. The ability to predict the response of abnormal occurrences acting on the machine is a major step toward preventing catastrophes. Simply stated, machine components that fail predictably, can prevent little accidents from becoming big accidents.
Prior maze-type locking devices, including U.S. Pat. No. 396,273, to Douds, U.S. Pat. No. 660,295, to Flinder, U.S. Pat. No. 3,824,815, to Darling, and U.S. Pat. No. 5,259,619, to Rosewarne, differ from the present invention in significant ways that reduce their utility vis-a-vis the present invention. These patents are incorporated herein by reference in their entirety. For example, the present invention: (1) provides an independently rotating pin wheel; (2) provides a single correct path defined by binary mechanical events; (3) provides an optional hold pawl to lock the device on the occurrence of an incorrect event; and (4) provides a fail-safe feature to prevent triggering of the locked device in the event of pin fracture.